This invention relates generally to optical systems and the components making up such systems, and, more particularly, to a guided-wave optical power divider in which an optical path is permanently altered based upon the impurity doping of the semiconductor body of the power divider.
With recent increased development of lasers and optical fibers, more attention has been directed to integrated optical systems or circuits and the components which make up these circuits. Particular concern has been directed to the area of optical communcations which operate at a wavelength of 1.3 .mu.m and beyond and the optical components such as couplers which are utilized therein. Since it has been recognized that optical components are capable of coupling efficiently to single-mode optical fibers, such optical components (couplers) become essential parts of fiber optic communication networks devoted to telecommunications or data communications applications.
More specifically, in a network of single-mode optical fibers, it is often desirable to distribute the optical signals from one set of fibers to a second set of fibers in a prescribed way. This can be accomplished with a planar integrated-optical component coupled to both sets of fibers. A typical prior art component for this purpose is a network of channel waveguides in the form of a series of directional couplers. Each coupler typically uses parallel channels with micron sized separation (spacing) and evanescent-wave coupling. At each coupler in the network, the amount of coupling (that is, the signal division) is determined by the channel spacing and the interaction length, both of which are governed by the photolithographic mask used to build the network.
The deficiency of the prior art is that a special new mask is required each time the signal distribution is changed. A precision, customized mask must be designed and generated in order to alter the cross guide coupling at any location (or set of locations) in the network. Furthermore, the position of connecting waveguides between couplers must be changed. It is therefore clearly evident that a need exists for improved optical couplers which do not require custom masks in their fabricaton.